PersistentServiceRegistrar.java

/*
 *
 * This is a simple Content Management System (CMS)
 * Copyright (C) 2009  Imran M Yousuf (imyousuf@smartitengineering.com)
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.smartitengineering.cms.spi.impl;

import com.google.inject.Inject;
import com.smartitengineering.cms.api.factory.write.PersistentWriter;
import com.smartitengineering.cms.api.type.MutableContentType;
import com.smartitengineering.cms.spi.persistence.PersistentService;
import java.util.Collections;
import java.util.Map;

/**
 * A registrar for beans that can be persisted. The idea is to register all
 * bean persistence service providers in this registrar.
 * @author imyousuf
 */
public class PersistentServiceRegistrar implements com.smartitengineering.cms.spi.persistence.PersistentServiceRegistrar {

  private Map<Class, PersistentService> register;

  @Inject
  /**
   * Initializes the registry keeper.
   */
  public PersistentServiceRegistrar(Map<Class, PersistentService> register) {
    this.register = register;
  }

  /**
   * An operation for retrieving the concrete implementation of persistent
   * service implementaion for the given persistable API bean.
   * @param <T> Should represent the class to be used in concrete SPI
   *					  implementations. For example, {@link MutableContentType}
   * @param writerClass The class to look for in the registrar.
   * @return Service for persisting the bean.
   * @see SmartSPI#getPersistentService(java.lang.Class)
   */
  @Override
  public <T extends PersistentWriter> PersistentService<T> getPersistentService(
      Class<T> writerClass) {
    return register.get(writerClass);
  }

  /**
   * Retrieve the registry of all persistent service implementations for
   * configured PersistentWriter children.
   * @return An unmodifieable version of the registry.
   */
  @Override
  public Map<Class, PersistentService> getRegister() {
    return Collections.unmodifiableMap(register);
  }

  /**
   * Resets the registry with the new registry. If the new registry is NULL or
   * empty the registry will achieve empty state but never NULL.
   * @param register The new registry.
   */
  public void setRegister(
      final Map<Class<? extends PersistentWriter>, PersistentService> register) {
    this.register.clear();
    if (register != null && !register.isEmpty()) {
      this.register.putAll(register);
    }
  }
}